Continuous Passive Motion (CPM) is a post-operative therapy that moves a joint passively through a prescribed range of motion for a prescribed period of time. Some of the proven benefits of CPM include the prevention of immobilization disease, improved joint nutrition, remodeling of joint surfaces, faster Range of Motion (ROM) gain, faster resorption and/or reduction of swelling conditions, decreased need for pain medication, and greater compliance to active and/or strengthening rehabilitation programs.
Immobilization disease can cause adhesion formation, joint contractures, and degeneration of articular and/or periarticular cartilage. Improved joint nutrition is characterized by enhanced delivery of oxygen and nutrients to the joints. With remodeling of joint surfaces, Wolf's law states that healing tissue will be laid down in a pattern dictated by the stresses imposed upon the tissue. CPM imposes stress upon the entire range of motion of the joint. Wolf's law results in healing tissue laid down over the entire range of motion of the joint.
Passive motion is a common therapy modality. CPM devices are utilized to attain the benefits of CPM. An appropriate CPM device is the Vector 2 Hand & Wrist Rehabilitation System (hereinafter “Vector 2”), available at Lantz Medical, 7750 Zionsville Road, Suite 800, Indianapolis, Ind. 46268. The Vector 2 Hand & Wrist Rehabilitation System Information document discloses indications, key features and benefits, and clinical advantages of the Vector 2. The Vector 2 Hand & Wrist Rehabilitation System Information document is currently available online at http://www.lantzmedical.com/website pdfs/V2%20Product%20Info%20pdf.pdf as of Dec. 13, 2009. The Vector 2 Hand & Wrist Rehabilitation System Information document is expressly incorporated by reference. Furthermore, the Vector 2 Application Guide discloses the major parts of Vector 2 and the steps of assembly for use. The Vector 2 Application Guide is currently available online at http://www.lantzmedical.com/website_pdfs/V2%20Application%20Guide.pdf as of Dec. 13, 2009. The Vector 2 Application Guide is expressly incorporated by reference. Finally, the present disclosure refers to parts of Vector 2 as described in the Vector 2 Hand & Wrist Rehabilitation System Information document and the Vector 2 Application Guide.
As shown in FIGS. 1A-1D, CPM device 10 may be utilized as a hand CPM, a wrist CPM, rehabilitation system for tenodesis, or combined motions, especially as a combined hand and wrist CPM. As a hand and wrist rehabilitative system, CPM device 10 flexes and extends interphalangeal joints 12 (including distal and proximal interphalangeal joints) and metacarpophalangeal joints 14 of hand 16 of a patient as well as flexes and extends wrist 18. CPM device 10 provides digital range of motion (digital ROM) from approximately negative twenty-one degrees (−) 21° (as shown in FIGS. 1A and 1B) to approximately three hundred and forty degrees(340°) (as shown in FIGS. 1C and 1D) as part of comprehensive motion therapy. CPM device 10 provides wrist 18 range of motion (wrist ROM) from approximately negative ninety degrees)(−90° (as shown in FIGS. 1B and 1D) to approximately ninety degrees (90°) (as shown in FIGS. 1A and 1C) as part of comprehensive motion therapy.
CPM device 10 comprises several major parts including forearm frame 20 (coupled to support 21), hand plate 22, hand drive unit 24, wrist drive unit 25, and leaf spring caterpillars 26 (also described as dynamic wire actuators). CPM device 10 provides at least one leaf spring caterpillar 26 for each digit 28 (also described throughout as a finger and/or thumb). As shown in each of FIGS. 1A-1D, CPM device 10 is configured to align with the dorsal side of the patient's forearm 30, wrist 18, and/or hand 16 in order to assist each finger 28. As described in greater detail in U.S. Provisional Patent Application No. 61/234,665, both Vector 1 and CPM device 10 are configured to align with the lateral side of the patient's forearm 30, wrist 18, and/or hand 16 for use with each thumb 28. Each leaf spring caterpillar 26 is malleable to allow for digital range of motion (digital ROM) considerations for each digit 28. CPM device 10 also includes several straps 31 (such as forearm straps 31 and cross straps 31 with thumb guard 31) and foam pads coupled to forearm frame 20 and hand plate 22. CPM device 10 also includes a custom glove (not shown) which fits over the patient's hand 16, wrist 18, and optionally patient's forearm 30.